Nontwist non-Hamiltonian systems

We show that the nontwist phenomena previously observed in Hamiltonian systems exist also in time-reversible non-Hamiltonian systems. In particular, we study the two standard collision/reconnection scenarios and we compute the parameter space breakup diagram of the shearless torus. Besides the Hamiltonian routes, the breakup may occur due to the onset of attractors. We study these phenomena in coupled phase oscillators and in non-area-preserving maps.Comment: 7 pages, 5 figure

Performance analysis of biodegradable municipal solid waste collection in the Czech Republic

ArticleThe article deals with the issues of biodegradable municipal solid waste management system, focusing on its separate collection. The two basic locations are compared – rural area and urban area. The emphasis is put on evaluation of individual biodegradable municipal solid waste collections development from 2012 to 2015. Individual technological performances of collection are also observed and evaluated (e.g. biodegradable municipal solid waste production, development of container quantity and collection frequency). The observed data also verify the efficiency of biodegradable municipal solid waste management compared to relative representation of this waste in rest municipal solid waste, which is produced in both locations. Also referential locations without separate biodegradable municipal solid waste collection are observed for evaluation. There are one locality of an urban area and one rural area too. The decrease of biodegradable municipal solid waste in rest of municipal solid waste at the basic rural researched area indicates that the directive on landfills could be followed with well-chosen technological parameters of separate biodegradable municipal solid waste collection at a given site. A statistically significant impact of separate biodegradable municipal solid waste production on relative amount of the biodegradable part in rest municipal solid waste has been demonstrated at the side of this basic rural area

A comparative case study of the efficiency of collection systems for paper and biodegradable municipal solid waste

ArticleThe need to increase municipal solid waste recycling rates has led to the study and analysis of recycling schemes from the perspective of the technical issues that may be involved. This paper compares two waste collection systems, which are operating in th e Vysočina region of the Czech Republic: a municipal solid waste collection system for paper (including cardboard) and a biodegradable municipal solid waste collection system. Both collection systems were introduced at different times to cover one selected urban area. The emphasis has been placed on an evaluation of the development of individual, separate collections between 2014 and 2016. Analysis of the technological operation and performance of the collections are observed and evaluated by measuring a ra nge of waste collection system indicators. Efficiency levels, especially when it comes to separate collections of both types of municipal solid waste, are compared to their relative representation in the remaining bulk of municipal solid waste. The changes in representation of these types of waste against those in the rest of the municipal solid waste shows which collection systems are more successful from the perspective of the implementation of the directive which covers landfill usage. The results also d escribe why systems could be more successful within the view of well - chosen or inappropriately - selected technological parameters for materials separation. The possibly statistically significant impact of paper waste production in terms of the relative amou nt of paper waste across the rest of the municipal solid waste has also been shown

Knowledge of packaging waste among czech university students

Received: February 1st, 2023 ; Accepted: June 16th, 2023 ; Published: June 28th, 2023 ; Correspondence: Ing. Shuran Zhao, [email protected] residential sector generates around 14% of the overall waste production in the Czech Republic. This essential share requires special attention to analyze with particular emphasis for citizen education, especially on young people. Thus, this research is dedicated to citizens' awareness about packaging waste to increase their knowledge. The experiment was conducted in the form of a survey, and students from a Czech university were asked to estimate the weight of the packaging waste presented to them in term to verify their knowledge about packaging waste. This experiment featured different groups of students over time. The result showed no difference in knowledge between these student groups over time. The long-term home study caused by COVID-19 did not appear to have affected students' knowledge of packaging waste. This study showed students' actual knowledge about packaging waste and highlighted the gap and importance of education in waste management

Comparison of physical composition of municipal solid waste in Czech municipalities and their potential in separation

Received: February 23rd, 2021 ; Accepted: May 2nd, 2021 ; Published: May 17th, 2021 ; Correspondence: [email protected] Republic has been moving from landfill-based waste system toward resourcebased waste management system with an increasing rate of recyclable waste in the last years (38.6% of recycling by material and 11.7% of energy recovery in 2018). However, landfill is still a popular way of mixed municipal solid waste (MMSW) disposal due to the low tax. In the Czech Republic, MMSW is collected from households by door-to-door system or recovery operations (Household Waste Recycling Centre) and only should consists of everyday items, which are further non-recyclable and non-reusable. However, a significant amount of recyclable waste can still be found in MMSW. Therefore, a good knowledge of the physical composition of MMSW is required to define strategy plans and improve waste management in municipalities. This work is aimed at comparing the physical composition of MMSW in the Czech Republic with small municipalities up to 2,999 inhabitants and big municipalities from 3,000 inhabitants to recognize the share of recyclable and non-recyclable waste in MSW and designate the potential of separation at source. Composition of MMSW was determined by a physical evaluation of waste collected from households in target municipalities which consists in a detailed manual sorting of waste into 13 specific groups according to their types, and weighting by a scale. We found that the real proportion of MMSW that could no longer be reused or recycled was much less than the amount disposed of in the municipal waste bins. A large part of MMSW consisted of organic waste together with food waste. This type of waste is especially useful when people turn it into compost to prevent the production of waste and it returns the nutrients back to the soil, closing the circle. The rate of recyclable waste was also high in many municipalities covered by our analyses, which indicated a lower rate of separation and reflected an insufficient sorting system in municipality and insufficient education of inhabitants. On the other hand, it points to the larger space of separation potential in households. In conclusion the evaluation emphasizes the improper proportion of MMSW in Czech municipalities. A lot of waste can be recycled but once it is thrown into black bins as MMSW, there is no chance that it will be reused/recycled. It therefore calls for measures to improve sorting at source, which will benefit municipal authorities in term of increasing recycle rates in order to comply with regulations and make a profit. We found the analysis of the physical composition of MMSW as a fundamental method for municipalities to verify the separation rate at the source, and it is recommended to conduct this analysis regularly and monitor developments

Langevin Thermostat for Rigid Body Dynamics

We present a new method for isothermal rigid body simulations using the quaternion representation and Langevin dynamics. It can be combined with the traditional Langevin or gradient (Brownian) dynamics for the translational degrees of freedom to correctly sample the NVT distribution in a simulation of rigid molecules. We propose simple, quasi-symplectic second-order numerical integrators and test their performance on the TIP4P model of water. We also investigate the optimal choice of thermostat parameters.Comment: 15 pages, 13 figures, 1 tabl

Stickiness in Hamiltonian systems: from sharply divided to hierarchical phase space

We investigate the dynamics of chaotic trajectories in simple yet physically important Hamiltonian systems with non-hierarchical borders between regular and chaotic regions with positive measures. We show that the stickiness to the border of the regular regions in systems with such a sharply divided phase space occurs through one-parameter families of marginally unstable periodic orbits and is characterized by an exponent \gamma= 2 for the asymptotic power-law decay of the distribution of recurrence times. Generic perturbations lead to systems with hierarchical phase space, where the stickiness is apparently enhanced due to the presence of infinitely many regular islands and Cantori. In this case, we show that the distribution of recurrence times can be composed of a sum of exponentials or a sum of power-laws, depending on the relative contribution of the primary and secondary structures of the hierarchy. Numerical verification of our main results are provided for area-preserving maps, mushroom billiards, and the newly defined magnetic mushroom billiards.Comment: To appear in Phys. Rev. E. A PDF version with higher resolution figures is available at http://www.pks.mpg.de/~edugal

Recent Consanguinity and Outbred Autozygosity Are Associated With Increased Risk of Late-Onset Alzheimer's Disease

Prior work in late-onset Alzheimer's disease (LOAD) has resulted in discrepant findings as to whether recent consanguinity and outbred autozygosity are associated with LOAD risk. In the current study, we tested the association between consanguinity and outbred autozygosity with LOAD in the largest such analysis to date, in which 20 LOAD GWAS datasets were retrieved through public databases. Our analyses were restricted to eight distinct ethnic groups: African-Caribbean, Ashkenazi-Jewish European, European-Caribbean, French-Canadian, Finnish European, North-Western European, South-Eastern European, and Yoruba African for a total of 21,492 unrelated subjects (11,196 LOAD and 10,296 controls). Recent consanguinity determination was performed using FSuite v1.0.3, according to subjects' ancestral background. The level of autozygosity in the outbred population was assessed by calculating inbreeding estimates based on the proportion (FROH) and the number (NROH) of runs of homozygosity (ROHs). We analyzed all eight ethnic groups using a fixed-effect meta-analysis, which showed a significant association of recent consanguinity with LOAD (N = 21,481; OR = 1.262, P = 3.6 × 10-4), independently of APOE∗4 (N = 21,468, OR = 1.237, P = 0.002), and years of education (N = 9,257; OR = 1.274, P = 0.020). Autozygosity in the outbred population was also associated with an increased risk of LOAD, both for FROH (N = 20,237; OR = 1.204, P = 0.030) and NROH metrics (N = 20,237; OR = 1.019, P = 0.006), independently of APOE∗4 [(FROH, N = 20,225; OR = 1.222, P = 0.029) (NROH, N = 20,225; OR = 1.019, P = 0.007)]. By leveraging the Alzheimer's Disease Sequencing Project (ADSP) whole-exome sequencing (WES) data, we determined that LOAD subjects do not show an enrichment of rare, risk-enhancing minor homozygote variants compared to the control population. A two-stage recessive GWAS using ADSP data from 201 consanguineous subjects in the discovery phase followed by validation in 10,469 subjects led to the identification of RPH3AL p.A303V (rs117190076) as a rare minor homozygote variant increasing the risk of LOAD [discovery: Genotype Relative Risk (GRR) = 46, P = 2.16 × 10-6; validation: GRR = 1.9, P = 8.0 × 10-4]. These results confirm that recent consanguinity and autozygosity in the outbred population increase risk for LOAD. Subsequent work, with increased samples sizes of consanguineous subjects, should accelerate the discovery of non-additive genetic effects in LOAD

On the classification of Kahler-Ricci solitons on Gorenstein del Pezzo surfaces

We give a classification of all pairs (X,v) of Gorenstein del Pezzo surfaces X and vector fields v which are K-stable in the sense of Berman-Nystrom and therefore are expected to admit a Kahler-Ricci solition. Moreover, we provide some new examples of Fano threefolds admitting a Kahler-Ricci soliton.Comment: 21 pages, ancillary files containing calculations in SageMath; minor correction